1. Field of the Invention
The present invention relates to a pad suitable for providing cushioning between the bottom of a railway rail and a rail foundation on which the rail stands.
2. Description of the Prior Art
A pad for providing cushioning between the bottom of a railway rail and a rail foundation on which the rail stands should desirably be made of a material which is durable and yet capable of deforming under load sufficiently to damp vibrations of the rail which would otherwise be transmitted deleteriously to the rail foundation. It is difficult in practice to reconcile these durability and vibration-damping requirements, particularly for heavy track conditions.
It has been found that, owing to the seepage of water, bearing particles of grit, sand, etc., between the pad and the rail foundation (commonly a concrete sleeper), erosion of the rail foundation and/or the pad can occur as the pad moves with respect to the surface of the rail foundation, owing to the passage of railway vehicles along the rail above it. Such erosion can be a particular problem where sand is applied to the rail to improve the grip of the wheels of a railway vehicle upon the rail.